Investigation of using gasoline-alcohol blends in a spark-ignition engine in terms of energy, exergy, economical, and environmental

Due to fluctuations in the prices of fossil-based fuels, growing environmental concerns and restrictions on exhaust emission norms, researchers are increasingly interested in alternative, sustainable, renewable and clean energy sources. Today, additives with high oxygen content are added to gasoline to reduce its environmental damages. Alcohols are the most important ones among them. Short-chain alcohols such as methanol and ethanol are preferred for gasoline engines, however a limited number of studies where long-chain alcohols are used was determined. In this study, the engine performance and exhaust emission values were determined using gasoline, PEN25 (25% 1-pentanol + 75% gasoline), HEK25 (25% 1-hexanol + 75% gasoline) and HEP25 (25% 1-heptanol + 75% gasoline) in a spark-ignition four-stroke engine with single cylinder and water cooling under constant speed (1500 rpm) and different load conditions (4, 8, 12 and 16 kg). The energy, exergy, economical, environmental and sustainability parameters were analyzed based on the obtained data. Finally, it was concluded that the addition of different heavy alcohols to gasoline increases fuel consumption and reduces thermal efficiency. Due to the low energy content of alcohols, the energy and exergy efficiencies of blended fuels were lower than that of gasoline. Although the economical analyses were affected adversely since alcohol prices are higher than gasoline prices, it was found that fuel blends gave better results than gasoline in terms of environmental aspect. If the production of heavy alcohols is increased, then their prices may decrease. This is one of the priority objectives for heavy alcohols being an alternative additive for gasoline.